Pythium Insidiosum Keratitis

An 83-year-old otherwise healthy female was referred to the BPEI ER for a progressive corneal ulcer. Exam in the left eye was notable for hand motions vision, normal IOP, and severe corneal ulcer associated with hypopyon and scleral extension. B-scan ultrasonography of the eye did not reveal evidence of endophthalmitis. Corneal and scleral cultures were obtained, and the patient was started on topical fortified antibiotics. Initial cultures were positive for mold, and the patient was started on topical natamycin. However, she continued to worsen so she was treated with rose Bengal-photodynamic antimicrobial therapy (RB-PDAT) as an investigational treatment to prevent a therapeutic penetrating keratoplasty (TPK). Final cultures came back positive for Pythium insidiosum, which is a rare cause of infectious keratitis not responsive to antifungals. The patient was also started on topical linezolid and azithromycin. The patient responded well to two rounds of RB-PDAT and infection was controlled without the need for a TPK.

Presentation Date: 10/01/2020

Issue Date: 02/12/2021